DE2440287A1 - AIR COMPRESSION SYSTEM - Google Patents

Description

PATENT LAWYERS

MANITZ, FINSTERWALD & GRÄMKOW

Munich, August 21, 1974-A 3027

AIRCO, INC.
85 Chestnut Ridge Road, Montvale, NJ 076 ^ 5

Luftkompressxons - System

The invention relates generally to an air compression system, and in particular an air compression system built up from individual building blocks or modules, the in certain industrial processes such as petrochemicals Processes, can be used.

509812/0303

DR. C. MANITZ · DIPU-INO. M. FINSTERWALD DIPL.-ING. W. GRAMKOW ZENTRALKASSE BAYER. FOLK BANKS MÖNCHEN 22. ROBERT-KOCH-STRASSE 1 7 STUTTGART SO (BAD CANNSTATT) MÖNCHEN. ACCOUNT NUMBER 7270

Certain processes are used in various fields of application of chemical process engineering Compressed air or compressed air is required, especially where more than one expansion is made will. A typical application for the use of the modular system according to the present invention The invention is the process for the production of nitric acid, in one process step it is gaseous Ammonia is mixed with compressed air; the mixed gases then go to a reactor supplied with a suitable, catalytic surface. After another treatment, the will resulting nitrogen oxides further with compressed air (at Presence of water) to react, from which nitric acid is formed. Similarly, can the compressed air for further reaction steps or for other tasks that arise in the overall process, can be used. Of course, the process steps shown here are only intended to be typical Represent processes during the operation of a system in which the present device can be used; they are mentioned here only to outline the general area in which the present Invention can be applied.

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A typical Ichemical process in which the present System can be used, but can generally be characterized as follows: the process is compressed or requires compressed air; this process also makes a hot, expandable gas available placed, which in a typical case is a hot residue or exhaust gas that turns out to be a product of a Combustion results in and a relatively low oxygen content Has.

In the conventional turbo machines for such chemical processes Ilochleistungs- devices that im generally have an output of more than 1,000 horsepower, in the form of individual compressors or compressors and individual steam and hot gas expansion units. These individual machines are generally used installed as low speed systems made up of multiple units; each will Machine aligned with great effort, which, however, is extremely time-consuming and often too unreliable Results. In addition, the multi-unit systems inevitably contain There are several warehouses in the entire system, as the individual machines, each with two warehouses, interact with one another be coupled; an additional gearbox or a gear train is often required to ensure the correct

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Speed of each unit to ensure.

A machine with a single shaft is described in US Pat. No. 3,696,637 for applications in which only low powers are required in the field of refrigeration technology or cooling technology; Due to its construction, however, this machine cannot be used where chemical process engineering requires high performance; Great advances have recently been made in this regard as multi-stage compressors or pre-compressors with a high pressure ratio in excess of k to 1 and high speed expansion units of the radial type with pressure ratios in excess of 5 ^to 1 have been developed; This made it possible to use an Iloch power air compression module with a common shaft in chemical process engineering.

The invention is therefore based, inter alia, on the task of creating a module for an air compression system, so that there is a compact, high-speed, high-performance turbo-machine in which only two bearings are used and which are used in a wide variety of chemical applications

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Process engineering can be used. Since the system only uses a single, common shaft, the module is very reliable and only requires one minimal maintenance. According to a preferred embodiment continuation the module is mounted on a rail, so that during assembly and alignment on the No problems occur at the place of use.

The elements of this modular air compression system include a common drive shaft, a multi-stage, high pressure ratio compressor and two turbo expansion units, one of which is steam driven while the other expansion unit is driven by hot exhaust gases or residual gases from the process itself . According to a preferred embodiment, the multi-stage compressor is a two-stage compressor, at least one of the two stages being operated at a pressure ratio which is greater than k to 1.

According to the present invention, an air compression system composed of individual components is used for applications in which high outputs are required are created, being on a common shaft

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The following parts are attached: a multi-stage air compressor with high pressure ratio, which the chemical Supplies air to processes in which the system is used; a high-pressure hot gas radial turbine serving as an expansion stage, which is driven by the hot residual gases of the processes and on a common Shaft is arranged on one side of the compressor; and finally a steam turbine that has the starting power and other, additional assistance supplies and on of the common shaft is arranged on the side opposite to the compressor. Flank two main camps the multi-stage compressor between the expansion units. For certain chemical processes, a secondary turbomachine can be provided that is based on a second shaft contains the following parts: a low pressure gas expansion unit, which is connected to receive the exhaust gases from the high pressure expansion unit and is driven by them; and an auxiliary gas compressor by the low pressure expansion unit is driven. The gas booster compressor receives gases from the chemical process that compresses and fed back into the processes for further use. The various elements of the system, including the controls and the control panel, are completely as one unit on a common Rail mounted, making it a very reliable one

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Results in a unit that requires a minimal number of connections and ports to install; It is also possible to check the entire, integrated module in the production facility

The invention thus creates an air compression system, that in chemical process engineering can be used. A primary module of the Luftkomprcssions-Systens contains on a common Shaft the following parts: a multi-stage compressor with a high pressure ratio, which compressed the process Supplies air; a pair of bearings that the Hold common shaft and enclose the multi-stage compressor between them; a steam turbine is arranged on one end of the common shaft to accommodate the air compression module if required to supply the power required for the start and auxiliary power during operation; to the opposite end of the common shaft is a hot gas expansion device in radial construction provided that picks up the hot gases from the process and expands them, making them the main source of energy for the air compression module. So this air pressure module delivers one

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high performance and operation at a relatively high speed so that it can be used in chemical engineering; furthermore, the module is mounted on a rail, so that it can be installed easily, and the maintenance to ensure reliable operation is very low overall. Further, the module may further mi L, to carry out the processes bcnö_ tigton Turboniaschiiicm be gemeinsameingesotzt, if making the respective process steps required.

The invention is illustrated below with the aid of exemplary embodiments explained in more detail with reference to the accompanying drawing.

Show it:

Figure 1 is a perspective external view of a inodular air compression system according to the present Invention;

FIG. 2 is a side view, partly in section, of the base unit forming the base unit used in FIG Air compression module;

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Figure 3 is a simplified block diagram in which is shown schematically how the various components of the present invention are in the system function; and

Figure k is a schematic block diagram generally similar to that shown in Figure 3, but showing the control valve arrangement used in the system.

In Fig. Ι isü a perspective external view an air compression system consisting of individual components according to the present invention shown. It is used in a system for chemical process engineering an air compression module having a shaft 10 attached to a further secondary turbo-compressor unit 11 via a rail connection.

In detail it can be seen that a base plate is provided in the form of a rail 12 on which the Air compression module 10 and the secondary turbo compressor 11 are attached. Thereby the air compression -Module 10 and the secondary turbo compressor 11 supported by frame parts l4 and l6, which like in turn, with their base surfaces on the rail 12

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are consolidated. An oil reservoir is in a similar vein 18 along with Ölpurapen 20, an oil collector 22 and a separator or demister 24 at the distal end of the Rail 12 attached, these individual elements as part of the lubrication system for the entire circulation or Serve circulatory system, which is attached to a common base. At the front end of the rail 12 a control panel 26 is attached, which the various for the control serving measuring devices, actuating switches, etc. carries, which indicate the operating status or the operational run of the module. The various measuring devices and other control devices, apart from their incorporation into the present system (as in the following will be described) are among the conventional elements of such a system.

The basic unit air compression module 10 which forms part of the present invention contains a steam turbine 23, which can be single-stage or multi-stage; furthermore, the module 10 contains a two-stage Air compressor 30 and a low pressure hot gas expansion unit 32. The secondary turbo compressor unit 11 contains a low pressure expansion unit 34 and a supercharging or additional compressor 36 (gas boost compressor) providing additional power . An intercooler is indicated generally at 38.

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In Fig. 2, the air compression module 10 is shown, the steam turbine 28, the viclstufigen Compressor 30 and the hot gas expansion unit 32 contains.

First, the steam turbine 23 will be explained; a steam inlet 40 is provided so that the steam can enter the turbine housing k2 when it flows into a screw or spiral; it is axially generated by pressure or pulse blades k6 on a turbine ^runner! iu expands, the expanded steam being discharged through the turbine outlet 50 to the outside. The steam turbine itself is a high-performance unit with axial flow, so a so-called. Axial turbine, with a high pressure ratio j the size of the steam turbine is sufficient that the module 10 can be started by steam power. According to the illustration, it is a single-stage machine; however, as mentioned above, a multi-stage construction can also be used. After the air compression module 10 has been put into operation, the chemical process itself can only generate an amount of hot residue or exhaust gases in order to drive or supply the hot gas expansion unit 32 with energy, whereby the entire energy for the run the module 10 is delivered; as alternative

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for this purpose, the steam turbine 28 can continue to be kept in operation in order to provide the system with additional energy to feed.

The Turbincnläufer 'ISS is mounted on a common shaft 52 of the module, the geraäß the representation forms the Hauptdrehwellc for Luf tkonipress i ons module 10, of the multi-stage air compressor 30 and the He j ßgas-E:; contains pansionsoinheit 32nd

According to the illustration, the compressor 30 is two-stage, wherein it has in its first stage 31 an inlet 5'ϊ to air, which is approximately on Ambient pressure is to be recorded and a Kor.ipressor inlet guide. 56 feed, where a variable guide vane 5 <"is arranged, ut.i die To vary air inflow. The variable guide vane 58 can be provided by a traditional institution, like Ζ.Γ3. a star arm 60, riveted from a Pu rivet outside of the entire compressor housing. In the conventional way, the air is turned by rotating Compressor license 62 is withdrawn and during the Discharge in the outlet line 6 ^ i compressed, after which the compressed air out into the annular outlet chamber 66 to the outlet of the first stage (in Fig. 2 not shown) is forced. Self-

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It will be understood that the compressor blades 62 are attached to the main shaft 52. At least one of the stages of the two-stage compressor, according to a preferred embodiment the first stage, is operated at a pressure ratio which is greater than ¹ L to 1.

Similarly, in the second stage compressor 33 air which is at approximately ambient pressure, into an inlet 68 of the second stage, an inlet line? O and in an outlet line 7 ^'1 to an annular Auslaßkamraer and through an outlet 78 by the guide vanes 72 second stage led to the outside. As shown, the second stage is not provided with variable blades for performing control. Again, the blades 72 of the second stage 33 of the compressor are attached to the common shaft 52.

A hot gas expansion unit 32 is on the remaining one Arranged at the end of the common shaft 52. The hot gas expansion unit 32 has a housing 80 an: inlet (not shown in. Fig. 2) to to receive the hot exhaust gases or residual gases of the chemical process and the hot gas in an annular To introduce inlet chamber 82. From the inlet chamber 82 the hot gas is passed through a radial inlet

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line 04 and rotating blades 86 expanded; the expanded hot gas is led to the outside through an outlet 88 of the expansion unit. This expansion unit 32 uses a radial inflow, so has the design of a radial turbine to the to expand very high pressure ratios, i.e. ratios above 5 to 1, as is the case for the Application areas in chemical engineering is required. The high pressure ratios allowed borrowed the use of a design in which only a minimal number of expansion stages are required is; Far Aiii this construction is better suitable for high performance requirements as one Expansion unit in axial design. For a typical Radial type hot gas expansion unit, the power capacity can be on the order of approximately 15,000 horsepower to about 20,000 horsepower.

In the overall arrangement of the air compression module 10 is the common shaft 52 only through two days 90 and 92, which are located on each side of the multi-stage compressor 30. The hot gas expansion unit 32 and the steam turbine 28 are cantilevered on the shaft 52 at opposite ends arranged. The overall module itself is generally

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a sytem rait high speed and high performance, whereby the typical speeds in the range from 10,000 to 20,000 revolutions per minute and the achievements over 1500 hp.

As already mentioned, the air compression module 10 particularly suitable for use in the nitric acid process, generally in conjunction with additional, secondary turbo units; According to a preferred embodiment, sf locations are as shown in FIG is, all these parts are attached to the rail, especially where the hot gas expansion unit in nine Ilochdruck-Itadialstufc and a separate one The low pressure expansion stage is divided into a further compressor, e.g. a compressor to propel for nitrosos or nitrogen gas, as will be explained later.

For the application of the module described above in a process for the production of nitric acid is in Fi <-. 3 shows a \ ^r ereinfachtes Blockdiagizmm schematically shows how cooperating various components illustrated in FIGS. 1 and 2. The parts listed in FIG. 3 are identified with reference numerals which correspond to those of the similar elements according to FIGS. 1 and 2. It should

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- ιό -

be emphasized here again that the scope This invention is not intended to be limited to that specific process or environmental constraints; this device can also be used in otherxx chemical processes, including for example the following processes include: Komprdssionssysteiie for the exhaust gases or residual gases from a blasting gelatine factory (SNG factory), methanol factories or others Iloch power application area, where a process Compressed air is required as a by-product the process hot Riickstaiidsga.se occur, diο for regaining power via expansion are suitable.

According to FIG. 3, the air compression module 10 contains the steam turbine 23, the first compressor stage 31, the second compressor stage 33 (which have the two stages of the air compressor 30 according to FIG. 1), and a Hochdmick gas expansion turbine 32, all these parts being coaxial are mounted on the single, common drive or power shaft. As already mentioned, these various elements together form a module 10 of the air compression system. According to a preferred embodiment. =! form if.t d ^A - ο steam turbine 2ö after Ax't of an axial pressure tux'bino

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and, as will be explained later, it can be used both during the start-up of the module 10 and to provide additional auxiliary power during the further operation of the module 10. The steam is fed to the turbine 28 via the inlet 40 and exits the turbine via the outlet 50 from o The two stages of the radial turbo- compressor ^ O, namely the first compressor stage 31 and the second compressor stage JJ _1, are passed directly through the single-stage , high-pressure radial turbine 32 serving as an expansion unit and also driven by the steam turbine 28. The two compressor stages 31 and 33 are arranged back to back, with the main bearings located outside of each stage; An intercooler 38 is arranged between the stages. The first low-pressure stage 31 receives air through the air inlet 5 at a certain, fixed temperature, and passes this air on to the intercooler 38 at a much higher temperature 5 ^, for example, 30 C (86.F) at atmospheric pressure, while the temperature of the discharged air

the outlet 93.233.33 ° C (4-52 ° F) when the

solute pressure of 4.4 l Kg / cm (63 psia). The intercooler 38 has the conventional pipe and Mairte barrel construction, with the gas flowing through the pipes,

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- Io -

while the cooling water entered at the inlet 39 flows through the main jacket and exits from there via the outlet 4l. After passing through the intercooler 38, the air flows at the inlet 68 into the second compressor stage 33j, in a typical case having a temperature of about 116.6 ° C (242 F) and an absolute pressure of 4.20 kg / cm (60 psia).

The flow of air from the second compressor stage 33 passes through the outlet 78, the air in a typical case, an absolute pressure in the magnitude order of 8, 75 kg / cm (125 psia) and a temperature of 23O ⁰ C (446 ° F) Has. The compressed air is then delivered to a reaction chamber 94 which forms part of the process engineering system in which the module 10 is used. In a typical example, the compressed air in chamber 94 reacts with anronia, particularly ammonia gas, with the resultant effluent gases being provided to further downstream reaction points in the chemical process, which are apparently indicated by block 96. The hot gas expansion turbine 32 takes advantage of the process residue gas introduced through the inlet 8l which has passed through the block

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2U0287 - i $ -

identified chemical process results in one typical application in which the present air compression module 10 is used, can Residue gas has an absolute pressure on the order of 12.60 kg / cm (180 psia) and a temperature on the order of 648 C to 705 ° C (1200 to 1300 F). The residual gas can be expanded in two stages, whereby, as already indicated, only the hot gas expansion unit serving as the first stage 32 part of the air compression module 10 forms.

In a typical use case such as in the already mentioned nitric acid plant, the secondary turbo compressor 11 is used to process the nitrous gases generated in the processes occurring in block 96; these Gases have to be compressed further for the subsequent chemical reaction. These are nitrous gases accordingly via a line 98 and an inlet 100 fed to the additional compressor 36 for the nitj-osen gases. In a typical case, the inlet has the gas

at an absolute pressure of 707 kg / cm (110 psia) a temperature of 60 C (l'iO F) while it

2 an absolute pressure of 14: kg / cm at the outlet (200 psia) and a temperature of 135 ° C (275 ° F)

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Has. The compressor 36 is of the conventional, single stage radial type operated by a shaft 102 which is completely independent of the shaft 52. However, the power for the shaft 102 is supplied by the low pressure gas expansion turbine 3k which, as already mentioned, receives the exhaust gases providing the output power from the high pressure expansion turbine 32. The gas expansion turbine 34, together with the auxiliary compressor 36, can be viewed as a secondary turbomachine 11 with a shaft 102 which is free with respect to the shaft 52. In a typical case, the gas at the inlet 104 of the expansion turbine 34 has one

2 absolute pressure of the order of 2.24 kg / cm

(32 psia) and a temperature of 353 ° C (667 ° F). The exhaust gases from the low-pressure expander 34 are supplied (at an absolute pressure of about 1.029 kg / cm (l4,7 psia) and a temperature of 26O ⁰ C (502 ° F)) the outlet IO6. Additional energy for the additional compressor 36 can be generated by diverting a certain portion of the hot gas, which is usually supplied to the hot gas expansion unit 32, via a line 105 directly to the inlet Io4 of the expansion turbine 34 with the activation of a suitable control valve.

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2U0287

The sliding systems and bearings used in the present air compression module are of conventional construction, so that they are not shown here in detail; The individual elements of the lubrication systems have already been mentioned in general with reference to FIG. 1 and contain the oil reservoir 18, oil pumps, one of which has the reference number 20, an oil collector 22, a separator or demister 2k and other conventional elements such as oil filters and coolers .

Figure 4 is a schematic block diagram generally similar to that shown in Figure 3, but showing the control valve arrangement used in accordance with one embodiment of this invention. In the control for the auxiliary steam turbine 28, it can be seen that the steam inlet line kO to the steam turbine 28 can run either through the main turbine valve 112 or through an auxiliary start valve II4. The starting and stopping of the air compression module 10 are controlled by these valves 112 and II4. In detail, the inlet valves 112 and 114 for the steam turbine are opened during the start-up operation, so that sufficient energy is obtained from the turbine 28 to produce a corresponding pressure

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^d it to receive compressed air for the block 96 shown in process. However, as soon as a sufficient amount of residual gas has developed in these chemical processes, the auxiliary start valve 11A can be closed and the steam turbine is only used, if necessary, to provide auxiliary energy. A regulator II6 is connected to a speed control valve via a schematically indicated connection II8 in order to regulate the speed of the turbine 28 in a conventional manner. A similar controller 120 regulates the speed of the auxiliary compressor 36.

The air temperature of the compressed air passing through the line 122 flows is controlled by controlling the heat dissipation in the intercooler 38. This is achieved in detail in that the air temperature of the compressor by (not shown) Sensor is detected, the output of this sensor is used to control a control valve 124 for the water flow in the cooling water pipe to adjust. Furthermore, the compressor stages 31 and 32 are in the path of the gas flow a relief or outlet valve 126 serving as an intermediate stage and a bypass line 128 and a bypass or safety valve I30 is provided, which can serve a certain proportion

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of the gases to lead to the intercooler 38. A multi-stage compressor 30 of the present type shows a certain instability at certain operating points due to incorrect adaptation between the front and rear stages is generated at a speed that is certain fractions corresponds to the rated speed. While the stages in the inlet areas are at the projected speed are close to their optimum, a completely different result occurs at a lower speed Image. If the speed of the compressor is reduced from the projected value, the front one inclines The flow passing through the stage tends to decrease linearly with the speed, but with that of the The output power density supplied to the second stage decreases with the square of the speed. Because the area the second stage is fixed, the air speed must be there relative to the rotor speed. rise. Therefore, the engine can approach a throttling condition in which the speed is not may increase so that the relative speed level at the inlet of the first stage of the compressor is decreased. This means that the front step tends to block or stop while the second stage a restricted flow condition

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approaching. Since this condition arises from the fact that an excessive flow is supplied to the second stage, it can be effectively eliminated by controlling the relief valve 126 serving as an intermediate stage is opened.

The speed of the turbo compressor stages 31 and 33 is controlled by the supply of the fluid media used as working media (steam and residue gas ) to the high pressure expansion unit 32 and to the steam turbine 28 is throttled. This is done using of the valve 112 already described and a valve 132 in a line 13 ^ achieved. A bypass or Safety valve I36 in a line 138 which runs from the second compressor stage 33, serves to enable a control function in the event of a rapid increase in performance »This is for the System start-up required. In detail, every tendency leads to an uncontrolled increase of the power at the second stage 33 of the compressor to the fact that the safety valve I36 opens, whereby the discharge pressure and thus also the tendency to increase performance is reduced.

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It goes without saying that the secondary turbomachine according to FIG. 1 is not in all applications the invention required. This means that depending on the process engineering system, using the present invention, an auxiliary compressor 36 may or may not be required not. Accordingly, an air compressor module unit 10, like those of FIG. 2, can be used alone, while in certain others Areas of application with additional turbo-compressor units attached to the rail, as shown in Fig. 1 can be used; these applications are also within the scope of this one Invention.

Although the present invention has been described in detail based on specific embodiments it will be apparent that those skilled in the art can make numerous modifications to the invention can make, which are always in the range of the teaching described here. Therefore the invention and the idea of the invention only through the scope, of the following claims.

- patent claims -

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Claims (12)

Claims ι 1} Air compression module for chemical processes that require compressed air and in which hot, expandable gases are available as a usable waste product, characterized by a common main shaft (52), by an axial steam turbine (28) on one End of the shaft (52), which is used to drive the shaft (52), through a hot gas expansion unit in radial design (32) at the other end of the shaft (52), which the hot, expandable gas supplied by the chemical process for the drive of the shaft (52) expands, and by a multi-stage compressor (30) with a high pressure ratio, which is arranged between the steam turbine (23) and the hot gas expansion unit (32) on the shaft (52) and is driven by it, . wherein the air compressor (30) supplies compressed air to the chemical process. 2. Air compression module according to claim 1, characterized characterized in that a control arrangement is provided which controls the supply of energy from the turbine (28) to the shaft (52) terminated when the hot gas expansion unit (32) of the shaft (52) has a predetermined one Amount of energy supplied. 509812/0303 3. Air compression module according to one of claims 1 or 2, characterized in that the multi-stage compressor (30) has a first Kompressxonsstufe (31) and a second Kompressxonsstufe (33) and an intermediate cooler (28), which from the first stage (31) to the second stage (33) cools air, and that at least one of the compression stages (31> 33) is operated at a pressure ratio which is above k to 1. 4. Air compression module according to claim 3i, characterized in that that this one stage is the first compression stage (31). 5. Air compression module according to one of claims 1 to 4t, characterized in that the hot gas expansion unit (32) has a pressure ratio which is above 5 ^to 1, and an output of at least 1500 PS. 6. Air compression module according to one of claims 1 to 5 » characterized in that the common main shaft (52) rotates at a speed exceeding 10,000 Revolutions per minute. 509812/0303 7 · Air compression module according to one of the claims 1 to 6, characterized in that the module (10) is mounted on a rail. 8. Air compression system for chemical processes, too whose implementation requires compressed air and where hot, expandable gases are considered usable Waste product are available, characterized by an air compression module (10) with a first, rotatable shaft (52), with an axial steam turbine (28) on one end of the shaft (52), which the Shaft (52) drives, with a hot gas expansion unit (32) in radial construction on the opposite End of the shaft (52), which is used to drive the shaft (52), the hot, expandable, of the chemical process supplied gases expanded, and with a multi-stage compressor (30) on the Shaft (52) is arranged between the steam turbine (28) and the hot gas expansion unit (32) and is driven by the shaft (52), the air compressor (30) being compressed by the chemical process Air is supplied, and through a secondary turbomachine (11), which has a second hot gas expansion unit (3 ^) »the hot gases from the first hot gas expansion unit (32) to the next Expansion-this takes in gases, and a compressor (36), which is fed directly through the second hot gas 509812/0303 Expansion unit (3 ^) is driven and others Gases compressed for the chemical process. 9. Air compression system according to claim 8, characterized in that the multi-stage compressor (30) has a first and a second compression stage (31 »33), and that at least one of the compression stages is operated at a pressure ratio which is above k . 10. Air compression system according to claim 9 »thereby characterized in that this compression stage is the first Compression level (31) is. 11. Air compression system according to one of the claims 8 to 10, characterized in that the air compression module (10) and the secondary turbomachine (11) each on a common rail (12) are attached. 12. Air compression system according to one of the claims 8 to 11, characterized in that the hot gas expansion unit (34) a pressure ratio in excess of 5 to 1 and an output of at least Has 15oo horsepower. 50981 2/0303 13 · Air compression system according to one of the claims 8 to 12, characterized in that the first rotatable shaft (52) with more than 10,000 Rotates revolutions per minute. 509812/0303 Lee ite